adding note on limitations
adding note on limitations

shenzhouzd/update,emilhem/node-unblocker,haveacc/a,nfriedly/node-unblocker,haveacc/a,nfriedly/node-unblocker,krrishd/node-unblocker,krrishd/node-unblocker,shenzhouzd/update,emilhem/node-unblocker